My Apple Watch won’t track mileage while bike ride

Hello and welcome to Apple Support Communities, mockingjay77!

I understand your Apple Watch wasn't tracking mileage while riding your bike. I'd be happy to provide information to help you address this.

Make sure you've started a cycling workout: Work out with your Apple Watch

Also, check out these articles for additional help:

Workout types on Apple Watch

"Cycling

Choose Indoor Cycle for activities like taking a spin class or riding a stationary bike. Choose Outdoor Cycle for riding a bicycle outside.

Depending on your Apple Watch, you might need to bring your iPhone with you to track certain metrics:

Speed and distance: Apple Watch Series 2 or later has built-in GPS to track these metrics and provide a map of your outdoor cycle in the workout summary on your iPhone. For Apple Watch Series 1 or earlier, bring your iPhone along to track your speed and distance. 

Elevation: Apple Watch Series 3 or later has a built-in altimeter to track this metric. For Apple Watch Series 2 or earlier, bring your iPhone along to track your elevation".

Calibrating your Apple Watch for improved Workout and Activity accuracy

Thank you for using Apple Support Communities.

Enjoy your day!

My Apple Watch series 2 will not track any mileage when I use it on a bike ride. It tracks time, active and total calories, elevation gain, avg. heart rate, but will NOT track distance or avg. speed. What coul be causing this? By the way, I have my phone with me on the bike when I am using the workout app.